A scanner can read an encoded image formed on a sheet. The encoded image is, for example, a barcode. When reading the barcode formed on the sheet, the scanner detects the barcode by searching the entire area of the sheet. Therefore, it takes time to read the barcode in some cases. Alternatively, a user sets a reading position on the sheet by using a personal computer or the like. The scanner reads the barcode from the reading position on the sheet to be read. In this case, the time for the scanner to read the barcode is shortened. However, the work of setting the reading position is complicated, and it takes time to set up in some cases.